After you've created an email account
within your DirectAdmin control panel, you will want to access your email account(s). One way to do so is by using Roundcube Webmail.
There are 2 ways to access webmail
1) Open your web browser and go to yourdomain.com/roundcube/ (replace yourdomain.com with your actual domain name)
a. Once you're there, enter your full email address and password to login
2) Login to your DirectAdmin control panel
a. Go to the E-mail Manager
section and click E-mail Accounts
b. Here you will see a list of all of your email accounts. Click the blue icon to the right of the email account you want to access and it will automatically log you in to that account.